Block #424,977

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 3/1/2014, 1:45:45 PM · Difficulty 10.3662 · 6,371,576 confirmations

1CC
Cunningham Chain of the First Kind

A sequence where each prime is double the previous prime plus one.

Block Header
Block Hash
c21f263ff5866714bdfe7cedec373c0409ea054b38f8aaa1e1f9fea5953278a1

Height

#424,977

Difficulty

10.366179

Transactions

2

Size

1.26 KB

Version

2

Bits

0a5dbdec

Nonce

61,010

Timestamp

3/1/2014, 1:45:45 PM

Confirmations

6,371,576

Merkle Root

aa6f6e16e8c47e46867ecbe0118115eb5094afc722cf1d7f607fa2b0284cd803
Prime Chain Origin

This is the prime chain origin stored in the block header. It is a composite number (not prime itself) — it equals the first prime in the chain multiplied by a primorial. The origin anchors the entire chain to this specific block.

2.479 × 10⁹⁷(98-digit number)
24791664686269885135…94469515657855567279
Discovered Prime Numbers
p_k = 2^k × origin − 1

These are the actual prime numbers discovered by this block, computed using the verified Primecoin formula. Each number has been independently confirmed to pass the Fermat primality test. Use the FactorDB links to verify any number independently.

1
origin − 1
2.479 × 10⁹⁷(98-digit number)
24791664686269885135…94469515657855567279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
4.958 × 10⁹⁷(98-digit number)
49583329372539770270…88939031315711134559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
9.916 × 10⁹⁷(98-digit number)
99166658745079540541…77878062631422269119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.983 × 10⁹⁸(99-digit number)
19833331749015908108…55756125262844538239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.966 × 10⁹⁸(99-digit number)
39666663498031816216…11512250525689076479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
7.933 × 10⁹⁸(99-digit number)
79333326996063632432…23024501051378152959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.586 × 10⁹⁹(100-digit number)
15866665399212726486…46049002102756305919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
3.173 × 10⁹⁹(100-digit number)
31733330798425452973…92098004205512611839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
6.346 × 10⁹⁹(100-digit number)
63466661596850905946…84196008411025223679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.269 × 10¹⁰⁰(101-digit number)
12693332319370181189…68392016822050447359
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 10 consecutive prime numbers forming a Cunningham Chain of the First Kind. The prime chain origin — the large number shown above — anchors the chain and is divisible by a primorial (the product of small primes), cryptographically tying these prime numbers to this specific block.

★★☆☆☆
Rarity
UncommonChain length 10

Roughly 1 in 100 blocks. Solid but expected in a healthy network.

How Primecoin's Proof-of-Work Constructs These Primes

Primecoin stores a value called the prime chain origin in each block. The miner found a large integer such that when divided by a primorial (the product of small primes: 2 × 3 × 5 × 7 × …), the result is the first prime in the chain. The origin is deliberately divisible by this primorial — that divisibility is part of the proof.

Prime Chain Origin = First Prime × Primorial (2·3·5·7·11·…)
Source: Primecoin prime.cpp — CheckPrimeProofOfWork()

This is why the origin has many small prime factors — those factors are the primorial divisor. The chain then extends from the first prime using the 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,616,422 XPM·at block #6,796,552 · updates every 60s
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